Commitments And Contingencies (Pumped-Storage Hydroelectric Facility Breach) (Detail) - Union Electric Company $ in Millions	Sep. 30, 2015 USD ($)
Loss Contingencies [Line Items]
Insurance settlements receivable	$ 41
Insurance Claim	$ 54

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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